Traditional cable modems operate using frequency-division duplexed communications; that is, communication from the cable modems to their corresponding cable modem termination system (CMTS) (i.e., uplink communication) occurs in a different frequency band than communications from the CMTS to the cable modem (i.e., downlink communication). Recent work in the electronic communications field has led to advancements in developing full-duplex communications systems; these systems, if implemented successfully, could allow for more efficient allocation of communication in a given bandwidth spectrum. One major roadblock to successful implementation of full-duplex communications is the problem of self-interference. While progress has been made in this area, many solutions intended to address self-interference are less than ideal for the particular needs of cable modem communication. Thus, there is a need in the electronic communications field to create new and useful analog self-interference cancellation systems for CMTS. This invention provides such new and useful systems.